Screwing



No. 62|,52a. Y Patented Mar. 2|, |899. n; luLunN.

SGREWING APPLIANGE PDB FDBMING SCREW THREADS 0N BOLTS, &c.

(Application led Dec. 27, 1897.) y

(No Model.) v

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if" l UNITED STATES PATENT OEEicEe I RICHARD KILBURN, OF MANCHESTER, ENGLAND.

SCRWING APPLIANCE FOR FORMING SCREW-THRADS ON BOLTS, &c.

SPECIFICATION forming part of Letters Patent No. 621,528, dated March 21, 1899.

Application filed December 2 7, 1897. Serial No. 663,526. (N0 model-l.

To all whom t Netty concern.'

Be it known that I, RICHARD KIL'BUEN, engineer, of 138 Church lane, Gorton, Manchester, in the county of Lancaster, England, have invented a new and useful Improvement in Screwing Appliances for Forming Screw- Threads on Bolts, &c., of which the following is a specification.

The principal object of my invention is to provide a ready adjustment to compensate for the wear of the dies or cutting-tools employed for the screwing of bolts or studs or other'articles or objects of different diameters, for the formation of screws of any desired length and diameter and,whenever desirable, screws of dierent sizes on different parts of the articles operated upon, and for the easy release of said articles Without unscrewing them from the dies.

A screwing appliance constructed according to my invention may be constructed with two or more dies or cutting-tools; but the invention is illustrated in the accompanying drawings by an appliance with three dies or cutting-tools.

Figure l represents a front elevation, Fig. 2 a side elevation, Fig. 3 a rear elevation, and Fig. 4 a longitudinal section on the plane indicated by the line 4 4 of Figs. l and 3, of the appliance having the cutting-dies in operative position. Fig. 5 is a front elevation corresponding with Figs. 1, 2, 3, and 4, but with part of the cover removed and part thereof shown in section. Fig. Gis a side elevation of said appliance with the dies in position to allow an article or object to be withdrawn without being unscrewed from it. Fig. 7 is a side view of one of the dies. Figs. 8 and 9 are respectively a side view and a top view of one of the details of the appliance to be hereinafter described.

'In the screwing appliance illustrated in the accompanying drawings, o: a a are three dies or cutting-tools mounted in corresponding radial grooves or channels, which are formed to receive them in a block or holder b. As shown, the holder b is made with a central passage throughout its length, so that articles or objects being operated upon may pass thereinwithout meeting with any obstrucarranged in conjunction with each die a sliding piece d, with a projection d engaging in a notch d* (see Fig. 7) in such die and pressed upon by a spring e, bearing at one end against such sliding piece d and at the other end against the end of a hole or passage in the 6o holder, lengthwise of which said sliding piece d is capable of being slid, said hole or passage being parallel to and in part in communication with the groove or channel in which said die ct is mounted, said spring c tending to force such sliding piece d, and with it said die, away from the centerline of the appliance.

The holder b is capable of being slid in the direction of the axis of the screwing appliance in a socket c, which may be of any suit- 7o able form, but as shown is in the form of a cylindrical tube. A groove is formed in the socket c, and a key bto fit into said groove is placed in a recess in the stem b2 of the holder Z?, so as to prevent the holder b and socket c from being turned in relation to each other, while permitting the holder b to be slid in the socket c in the direction of the axis of I the screwing appliance. In order to limit the movement of the holder lengthwise of 8o the socket c, a slot c of suitable length, as is hereinafter further explained, is formed in the socket c and a stud b3, projecting into such slot c and of a diameter approximately equal to the width of such slot, is screwed into the stem b2 of the holder b. Surrounding the holder I) and movable lengthwise of the stem b2 thereof are rings f gp The ring f is made `capable of being turned into and secured in different positions upon the ring g. In the 9o example shown a curved slot g' is formed in the ring g and a stud f is secured in the ring f and made to pass through the said slot g and provided with a washer and a nut f2.

In order` to prevent the holder b and ring g and the ring f when secured to the ring g from being turned in relation ,to each other and in order to limit the movement of such rings f g in the. direction of the axis or center line of the screwing appliance, as is hereinroo after further described, a recess c2 of suitable length is formed in the socket c and a screw g2 of a diameter approximately equal to the width of the recess c2 is screwed into the ring g, so as to project intothe recess. c2'. The ring f and the dies a are arranged to so react `upon each other that such ring f holds the dies a in operative position and is moved thereby in the direction opposite to that i11- dicated by the arrow A in the direction of the axis of the appliance in the release of the articles or objects operated upon and when moved in the direction of the arrow A when the holder b is moved in the opposite direction serves to restore the dies a to working position. To render vpossible this action and reaction, each die a is formed at its outer end in part with a surface a at right angles or approximately at right angles to its length and in part with a surface a2, inclined to its length, and the ring f is formed internally with faces f3, which when a screw-thread is being formed by the appliance form abutments or supports to prevent the dies from moving away from the bolt or article being operated upon. The internal faces f3 of the ring f are, as is clearly indicated in.Fig. 5, formed at equal distances from the center line of the appliance and made of such formspiral, for example-that by said ring being turned into a suitable position and then secured upon the ring g the dies ct may when bearing against said internal faces f3 with their faces a' be in proper position to act in the manner requisite upon said bolt or article. A cover h, which may conveniently be formed of a front plate h2, brazed into a tube 7b3, is secured by means of three set-screws 71. to the holder D, so as to keep the dies a, sliding pieces d, and springs e in position therein and to exclude dirt and particles of metal from the recesses and grooves in which the dies a and sliding pieces CZ and springs e are mounted and from the recesses between the ring fand holder b. The cover 71, and holder l) are formed with channels Z for the escape of the cuttings removed by the dies a from the bolt or article operated upon. The cover 7L is formed witha slot hthrongh which a key to turn the ring f in relation to the ring g may be passed into a hole f4, formed to receive it in the ring f. On the cover 7L, as indicated in the section in Fig; 5, is formed' a scale h5, which,with the hole f4, serves to indicate the relative positions of the rings f g.

The slot c' is made of such length that the holder Z) can be moved from the position in which it is indicated in Fig. 2 just so far that the faces ci' of the dies are moved out of contact with the edges f5 of the internal faces f3, respectively employed therewith, and the inclined faces a2 of such dies are just brought into contact with said edges f5. The recess c2 is made of such length that after the holder b has been moved in the socket c in the direction indicated by the arrow A to the extent permitted by the stud bsand slot c the springs e may move the dies ct outward away from the axis of the appliance far enough or, preferably, somewhat more than far enough to allow an article on which they may have formed screw-threads to be withdrawn without being unscrewed therefrom, butnot so far as to take their inclined surfaces a2 out of contact with the edges f5 of the internal faces f3, with which they respectively act.

The screwing appliance illustrated in the accompanying drawings is `for use mounted in a machine-a1athe,for exam ple-provided with anysuitable device-for example, such as is used in turret-lathes-by which the movement of the screwing appliance toward the part carrying the article to be operated upon or of such article toward the screwing appliance or the mutual approach of the screwing appliance and such article shall be interrupted as soon as a screw-thread of the required length has been formed on said article, and before the screwing of an article is commenced the appliance is set in the position illustrated by Figs. l, 2, 4, and 5. As soon as the relative movement ot` the screwing appliance and article ceases the dies a screw themselves for a very short time upon `said article and carry with them the holder b as far as the slot c and stud b3 permit and are then moved outward by the springs e, so as to become free of the screw-threads which they have formed and allow the article to bc withdrawn from the screwing appliance without it being necessary to stop or reverse the rotation of the screwing appliance or article, whichever may be revolving. The outward movement of the dies a by means of the inclined faces a2 moves the rings f g upon the socket c in a direction opposite to that in dicated by the arrow A to the extent permitted bythe recess c2 and stud g2. In order to again set the screwing appliance to form screwthreads,the attendant in charge ofthe machine in which such appliance is employed simply presses the rings f g in the direction indicated by the arrow A and the cover 7L in the opposite direction, and thereby causes the edges f5 of the internal faces f3 of the ringf to force the dies a inward toward the center line of the appliance and into engagement with the said faces f3.

The ring-j' affords a firm and solid abutment to the dies a when forming screw-threads and holding them in proper position assures the accurate formation of screw-threads, and the dies a, being moved in straight lines in relation to the articles operated upon in releasing them, are prevented from causing injury to them. The dies a, used in screwingheads made according to my invention, being simple in form, are easily made from steel bars and can be readily hardened without being liable to distortion.

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Screwing appliances constructed according to my invention may either be held stationary or be caused to revolve while in use, being capable of being made free from all projections upon their outer circular or cylin-` drical surfaces, and such appliances are also efcient and convenient in operation, simple in construction, and cheap to maintain in working condition and readily adjustable to compensate for the wear of the dies or the recutting thereof.

Vhat I claim as my invention isl. In an appliance for forming g screwthreads, the combination of dies formed with cutting edges upon their ends which are directed toward the center line of the appliance and with reacting parts at their other ends, a holder lwith grooves in which said dies are movable in the directions of their lengths and furnished with a cover bearing upon said dies and holding them in said grooves and so making them movable by said holder to and fro in the direction of the center line of the appliance, springs'to bear against said holder and press said dies outwardly therein, a socket longitudinally in which said holder is movable, means for limiting the movement of said holder in said socket and preventing it from being turned therein, two rings capable of being moved longitudinally of said socket and one of which is mounted upon the other and capable of being turned into and secured indifferent positions thereon and surrounds said dies and is furnished with approximately spiral faces to bear against the reacting faces of said dies, and means for limiting the movement of said rings upon said socket for preventing them from being turned upon said socket, all substantially as hereinbefore described.

2. In an appliance vvfor forming screwthreads, the combination of dies formed with cutting edges upon their ends which are directed toward the center line of the appliance and with reacting parts at their other ends, a holder-with grooves in which said dies are movable in the directions of their lengths and furnished with a cover bearing upon said dies and holding them in said grooves and so making them movable by said-holder to and fro in the direction of the center line of the appliance, springs to bear against said holder and press said dies outwardly therein, a socket longitudinally in which said holder is movable, a stud in said holder engaging with a slot in said socket to limit the longitudinal movement of said holder in said socket, a key in said holder engaging with a groove in said socket to prevent said holder from being turned in said socket, two rings capable of being moved longitudinally of said socket and one of Whichis mounted upon the other and capable of being turned into and secured in different positions thereon and surrounds said dies and is furnished with approximately spiral faces to bear against the reacting faces of said dies, and a pin in one of said rings engaging with a groove in -said socketfor limiting the movement of said rings upon said socket and for preventing them from being turned upon said socket, all substantially as hereinbefore described.

3. In an appliance for forming screwthreads, the combination of dies formed with 'holder to slide inwardand outward therein and furnished with projections engaging with notches in said dies, springs between said holder and said sliding pieces for pressing said sliding pieces and thereby said dies outwardly in said holder, a socket longitudinally in which said holder is movable, means for limiting the movement of said holder in said socket and preventing it from being turned therein, two rings capable of being moved longitudinally of'said socket and one of which is mounted upon the other and capable of being turned into and secured in dierent positions thereon and surrounds said dies and is furnished with approximately spiral faces to bear against the reacting faces of said dies, and means for limiting the longitudinal movement of said rings upon said socket and for preventing them from being turned upon said socket, all substantially as hereinbefore described; l

4:. In an appliance for forming screwthreads, the combination of dies formed with cutting edges upon their ends which are directed toward the center line of the appliance and with reacting parts at their other ends, a holder with grooves in which said dies are movable in the directions of their lengths and furnished with a coverbearing upon said dies and holding them in said grooves and so making them movable by said holder to and fro in the direction of the center line of the vent said holder from being turned in saidl socket, two rings capable of being moved lon- ICO IIO

git-udinally of said socket and one of which is mounted upon the other and capable of being turned into and Secured in different positions thereon and surrounds said dies and is furnished with approximately spiral faces to bear against the reacting parts of said dies, and a pin in one of said rings engaging with a groove in said socket for limiting the movement of said rings .upon said socket and for preventing them from being turned upon 1o said socket, all substantially as hereinbefore described.

RICHARD KILBURN.

Vitnesses:

HOWARD CHEETHAM, JAMES B. MILNER. 

